By the end, it was a reminder of those days when Elland Road would consider this kind of result as the norm rather than the exception. Leeds United had played with the competitive spirit for which they were once renowned and, though a club this size might not take too kindly to being described as giantkillers, there was still something fairly heroic about the way they bridged the gap with Tottenham Hotspur and sent the Premier League side toppling out of the FA Cup.

They were helped, undoubtedly, by the inability of several Tottenham players to grasp two things. One, the importance their club place on this competition as eight-time winners. Two, that a Leeds side managed by Neil Warnock would always cherish the possibility of cutting a top-division team down to size – and would be willing to cover every blade of glass to achieve it.

Yet Leeds did not win just because their players were quick to the ball, strong in the tackle and showed all the qualities associated with the classic FA Cup underdog. There was some refined football at times from the Championship's 11th-placed side and the decisive goal, from the left boot of Ross McCormack, was a beauty.

McCormack had played as though on a personal mission to show that Luciano Becchio's absence need not matter. Warnock had dropped his leading scorer in response to the Argentinian submitting a transfer request last week. The man who took his place was Luke Varney, whose lack of goals in his first season at Leeds has made him the subject of derision at times. Yet it was Varney's purposeful run and clinical finish that gave Leeds the lead and invigorated their self-esteem.

As for El Hadji Diouf, he had one of those games that made you wish he could have avoided those incidents that condemn him as one of the more reviled figures in football. Between the three of them, the Championship attackers were a constant menace for their top-tier opponents.

Clint Dempsey's clever, twisting header, eight minutes after McCormack had made it 2-0, ensured it would be a nerve-shredding finale but, overall, it was an undistinguished afternoon for Spurs. Scott Parker's display, indefatigable in midfield, should make him exempt from criticism and Gareth Bale was a formidable opponent once he stayed closer to the left wing in the second half rather than trying to run the game from every position.

This, however, was a scruffy Spurs performance. They can pass the ball a lot better and play with far better control. Perhaps this was the moment, too, when their luck ran out. All season they have been trying to scrape by with only two natural strikers. Emmanuel Adebayor's involvement in the Africa Cup of Nations had left Jermain Defoe as the last man standing but the England international was missing here because of a pelvic problem.

How Tottenham must wish it had been him on the end of their one clear chance to snatch a replay. Instead, the opportunity fell for the substitute, Jon Obika, who waited a fraction too long to get his shot away. Lee Peltier's saving tackle was brilliantly executed, as they had been all game.

Tottenham's ordeal had begun after a quarter of an hour when Michael Brown hooked an innocuous ball forward and suddenly Varney was running free on the left and making a beeline for goal. Kyle Naughton and, to a lesser extent, Steven Caulker had both been caught out after Diouf dangled out his leg and made no contact. The ball ran through and Varney ignored the temptation to square for McCormack, opened up his body and angled his shot past Brad Friedel.

Varney's finish was so impeccably delivered it felt like a trick of the mind that the 30-year-old has repeatedly threatened to exhaust the patience of the Elland Road crowd this season. He signed from Portsmouth last June and marked his debut, in their first match of the season, by scoring one of the goals in a 4-0 defeat of Shrewsbury in the Capital One Cup. The problem was he did not manage another in his next 18 appearances. All things considered, he took his goal with remarkable confidence.

Leeds could have been further ahead before half-time, Friedel saving at McCormack's feet at the end of the first half, but Tottenham's vulnerability in defence continued after the interval. Five minutes in, Gylfi Sigurdsson lost the ball in the Leeds half. Diouf released McCormack and when he turned inside Caulker, on the right-hand corner of the penalty area, it became apparent there was nobody to help him. McCormack took the only option that was really on, letting fly with his left foot. It was a wonderfully taken shot that was still rising as it hit the net.

Dempsey's header came from Bale's cross and, for 25 minutes, the Welshman tormented the Leeds right-back Sam Byram. One nutmeg, followed by an outrageous piece of skill, saw him sprinting away from three opponents. Yet Spurs did not play with the urgency that might have been expected for a team needing to score. For the most part, they also had two players, Dempsey and Sigurdsson, playing in attack despite being midfielders by trade. Leeds took advantage to remind their crowd of better times.